#include <bits/stdc++.h>
using namespace std;
ifstream in("lazy.in");
ofstream out("lazy.out");
typedef long long ll;
const int lim=2e5+4;
struct Op
{
    int x;
    int y;
    ll c1;
    ll c2;
    int ind;
};
vector<Op> edges;
bool ok[lim];
bool mycmp(Op a,Op b)
{
    if(a.c1==b.c1)
        return a.c2>b.c2;
    return a.c1<b.c1;
}
int link[lim];
int dim[lim];
int tata(int x)
{
    int cpy=x,aux;
    while(x!=link[x]) x=link[x];
    while(cpy!=link[cpy]) aux=cpy,cpy=link[cpy],link[aux]=x;
    return x;
}
void unite(int x,int y,int ind)
{
    x=tata(x);
    y=tata(y);
    if(x==y) return ;
    ok[ind]=true;
    if(dim[x]<dim[y]) swap(x,y);
    dim[x]+=dim[y];
    link[y]=x;
}
int main()
{
    int n,m,x,y;
    ll c1,c2;
    in>>n>>m;
    for(int i=1;i<=n;++i)
        link[i]=i,dim[i]=1;
    for(int i=1;i<=m;++i)
    {
        in>>x>>y>>c1>>c2;
        edges.push_back({x,y,c1,c2,i});
    }
    sort(edges.begin(),edges.end(),mycmp);
    for(auto e:edges)
        unite(e.x,e.y,e.ind);
    for(int i=1;i<=m;++i)
    if(ok[i]) out<<i<<'\n';
    return 0;
}